Electromagnetic rectifier and current redresser



R. A. ENGLER.

ELECTROMAGNETIC RECTIFIER AND CURRENT REDRESSER.

APPLICATION FILED MAR. 23, 1914. RENEWED NOV-12,1919.

4 SHEETSSHEET l.

1394,31 5, Patented Oct. 25,1921. 0

. WITNESSES. Q E 8 lNl/E/VTOR P/C/IdfdHf/l T M9/M. w By 9 f #16 ATTORNEYR. A. ENGLER.

ELECTROMAGNETIC RECTIFIER AND CURRENT REDRESSER.

APPLICATION FILED MAR. 23, I914. RENEWED NOV- 12,1919. 1,394,815.

Patented Oct. 25, 1921.

4 SHEETS-SHEET 2.

inns/7121.

R. A..ENGLER.

ELECTROMAGNETIC RECTIFIER AND CURRENT REDRESSER.

APPLICATION man MAR. 23, m4. RENEWED NOV. 12,1919. 1,394,815.

Patgnted "Oct. 25, 1921.

4 SHEETS-SHEET 3.

WITNESSES:

' Mm/Won T2 2, I P/Chardflfng/er.

ATTORNEY R. A. ENGLER.

ELECTROMAGNETIC RECTIFIER AND CURRENT REDRESSER. APPLICATION FILED MAR.23, 19 14. RENEWED NOV- 12,1919.

1,394,815, Patented Oct. 25; 1921,

4 SHEETS-SHEET 4.

Q I h 1- -1] c Mi A EJM WIT/VESSES: g INVEN TOQR 7; I F/c/m ra Eff/5765-7;

A TTOR/VEY PATENT OFFICE.

RICHARD A. anem a, or nuaooon. IOWA.

ELECTROMAGNETIC RECTIFIER AND CURRENT BEDBESSEB.

Specification of Letters Patent.

Patented Oct. 25,1921.

Application filed Iarclr28, 914, Serial No. 826,484. Renewed November12, 1919. Serial no. samaa.

To all whom it may concern: 7

Be i known that I, RICHARD A. ENGLER, citizen of the United Statesresiding at Dubuque, in the county of ubuque and State of Iowa, haveinvented a certain new and useful Improvement in ElectromagneticRectifiers and Current-Redressers, of which the following is a full,clear, concise, and exact description, reference being had to theaccompanying drawings, forming a part of this specification. Myinvention relates to systems of electrical distributions and involves anapparatus for changing the form of current. I have employed theapparatus of my invention i n rectifying alternating currents, in"converting direct current into alternating current and in convertingone alternating current into another.

When my invention is adapted'to the conversion of alternating intodirect current a wave throttling means is caused. to function insynchronism with alternate alternating current waves (that is waves.having one sign or direction) then to oppose the passage of current fromthe source of alternating current to the direct current system, saidthrottling means beinginert when the alternating current waves of thereverse sign or direction are being impressed, whereby the passage ofthese latter waves 'to the direct current system is. alone permitted bysaid wave throttler. Two such wave throttlers are preferably employed,one functioning.

only when alternating current waves of one direction are being impressedand the other functioning only when alternating currents of the reversedirection are being impressed, whereby the waves of one direction arepermitted passage by one throttler and the waves of the other directionare permitted passage bythe other throttler. The circuit connectionsassociated with these two devices by which current is permitted passageto the direct current system are such as to cause the alternatingcurrent waves of one direction to be reversed in the direction of theirpassage to the direct current system, while the other alternatingcurrent waves pass to such system in their normal direction. In this wayall of the alternating current waves are passed in uniform direction tothe.

direct current system to flow in such system as rectified alternating,or direct, current. The reactance employed in the throttling devices ispreferably furnished by inductnetic field into an alternating currentand also enables ratus thereof and in which ance which arises tothrottle the waves and disappears to permit their passage.

The equipment and method of my invention may be so employed as todispense with commutators and circuit opening and closmg contacts andwhich the rectifiers and reorganizers of the prior art havebeen devised.The invention enables the production of a rotating magfor converting a.direct current may fulfil purposes for the production of a rotatingmagnetic field for converting one alternating current into another bymutual induction.

' In the operation of my apparatus I prefer to ma e use of sets of coilswhich are caused to be non-differential or-inductive and differential ornon-inductive periodicallyand in synchronism with the waves of analternating current that is supplied, or that is generated by theapparatus itself.

In one case I use rotation of certain coils as the means for causingproper cooperation between the coils; in another case I employ openingand closing contacts, stationary. No sparking the latter method becausewith all coils can take place in the Lenz. or induction law is reversedin my combination of coils.. The invention and various uses to which itmay be put will be more fully explainedby reference to the accompanyingdrawings showing preferred embodiments of the appa- Figure l is a viewdiagrammatically illustrating the structure and some of the circuitarrangement of one equipment; Fig. 2 shows a slight modification of apart of the equipment of Fig. '1'; Fig. 3 is a view diagrammaticallyillustrating the structure and some of the circuit arrangement ofanother equipment; Figs. ie-and 5 are more complete diagrammaticillustrations of the equipment and operations illustrated respectivelyin Figs. 1 and 3, Fig. 6 is also further illustrative of the equipmentof Fig. 1; and F ig.-7 diagrammatically illustrates other operation s.

Like parts are indicated by similar characters of reference throughoutthe different figures.

Reference is first made to Figs. 1 and 4 which illustrate the,rectification of alternating current. There is employed a primary 10 ofa transformer 11 that is fed with alternating current from any source 10by 21 and rota nal connecte 'with terminal 20. At B twomeans of theleads 12 and 13. A secondary nect each with a unit in which therectificaplace, these units being calledtion takes A and B w ch are'ofsimilar constructlon. Central terminal 17, of the secondary, leadsto'the direct current feed wire 18. At unit A terminal 20 connects withthe end terminal 15 of the secondary. A stationary coil coil 22 eachhave one termisimilar coils 24 and 25 connect with terminal 23 which inturn connects with end terminal 16 of the secondary Current flowing fromeach end termina of the seconda therefore finds two paths at each unitthrough the coils of that unit, which paths at A again unite at 26 andat Bat 27; and

' thesetwo terminals connect with 28, which is the terminal of feed wire19.

.Terminals 20 and 26 at unit A connect with the terminals of therevolving coil 22 the other direct current throughthe medium. of brushes29 and 30 and slip rings 31 and 32, which latter re-.

volve with the coilwt In a similar manner coil 25 at B connects withterminals 23 and 27. At A, an iron path 33 is provided for the lines offorce from coils 21 and 22, while the magnetic core 34- is provided forthe same coils, which con may-either revolve with coil 22 or remainstationary. v

A synchronous alternating current motor 35 serves to drive the rotatingelements 22,

25 of units'A and B by means of a shaft which is represented by the line36. A shunt circuit from the ends 15 and 16 of the sec.- ondary 14 feedsthe ,motor 35. Lines 37 and 38 help form this shunt circuit and connectwith terminals 39 and 40 of the motor. In line 37 is inte osed acondenser 41 which serves to neutrallze the impedance in the motorcircuits; thus avoiding any lag of current in the secondary 14. Themotor may be in shunt of the primary 10 as indicated in Fi 2. The motormay be a small one, just big. enough to overcome friction. The next wave5 (Fig. 4) will be accom-- The rotating coils of both units A, B may begiven a forward or backward lead on the shaft so as to get theirrotation and co- Y in the rectification or de-recti operation with thestationary coil in step with the alternating current waves and passageof which theyare to control. In direct current line 18 are switches 42and 43.

With switch 42'closed and switch 43 open the battery 44 is cut outofcircuit. Closing switch 43 and opening switch 42 puts the battery inseries with the rectifier. At unit A is shown a coil 45 which {plays nopart the secondary of a transformer when my apparatus is used fortransforming by munating current waves are at their crests,

while when the coils of each unit are at right angles to each other thewaves are at zero. In the zero position of the coils-both r units areequal as to their inductive and non-inductive pro erties. horizontalarrows at A show the direction the lines of force from coils 21 and 22tend to take and since they are in the same direction the coils areinductive or non-differential. At B the linesof force from coil 24 tendto take the same direction as those at A, but coil 25 causes linestending to appear in the opposite direction which ,then makes these twocoils non-inductive or differential.

' Let the north pole be on the left and the south pole on. the right inboth units when inductlve, or to put this another we let it be said thatthe polarity of the stationary coils of both units are north on the leftand south on the right and of the rotating coils when parallel with thestationary coil, one is the same and the other the opposite and soalternately, for'convenience of description. However, the polarity inboth coils of a set may be reversed in one or both units because it isnot the direction of lines of a particular set of coils and poles, buthow the lines and poles cooperate in the units which is of importance.Therefore at unit A wave 0; (Fi 4) .is throttled, whileat unit B itisallowe to pass. This being the case current flows as shown by the arrowsin .Fig. 1 and the full line arrows in Fig. 4 and the half of thesecondary 14 from 17 to 16 is active while the other half is dead,omitting reference to the driving motor current.

The straight Ill panied by a reverse order of conditions bebut therotation may be in either direction.

The alternating "current feed wires 12 and cation 'but is 13 may connectat 50 and 51, cutting out the rimary 10. In this event the secondary 14ecomes an auto-transformer or compensatorand the apparatus operatesexactly 'asbefore. The auto-transformer coils may efiicient.

factor, thereby making the apparatus very Assuming that coil 22 startsfrom a zero" the circ e A, Fig. 4), as such coil turns through its firstquarterin a'clockwise di rection to the posltion shown in Fig. 1, the

first half of-wave a starts from zero and ends at its maximum, coil 22then having the position indicated in Fig. 1. One quarter turn of coil22 causes an eighth turn and a tendency to increase in strength of animaginary resultant. Enough current flows in the units when passingthrough the no load or inductive intervals "or periods to overcome theresistance of the coils, being in this respect like the primary of atransformer at no load. 7 A very weak resultant only appears, whichhaving no value, I call imaginary. As the coil 22 turns through itssecond quarter the second half of wave a drops from maximum to zero andthe ima nary resultant falls to zero. As will Ti e noticed the coils 21and 22 so cooperate as to make them inductive during this first halfrevolution, which therefore enables unit A to throttle any current thattends to flow through them during the v.ffow of wave a. At the end ofthe third quarter turn of coil 22 the next wave 1) is brought to maximumbut in reversed direction to the first wave a. The imaginaryresultant-therefore in rising changes its polarity. The two fields ofthe coils 21 and 22 now oppose each other exactly. Durin the lastquarter turn of coil 22 the lastfiialfof wave 6 drops from maximum tozero and the imaginary resultant willv fall. The coils .22 and 21 in thelast half revolution of coil 22 thus cooperate in such manner that thewave 6 is permitted to be passed through the coils of unit I .A whenthus non-inductively disposed. The

imaginary resultant has only assed over an arc of 180 for a 360 are 0travel of the soil 22, The operations above described are alsoillustrated in part in Fig. 6. The re sult'ant is indicated by dot anddash lines. 7

Unit B similarly operates to'pass wave a while the passage of such wavethrough unit A is prevented and obstructs the passage through it ofwave 1) while unit A permits the passage of this latter wave. Thedecrease of resultant due to the increase of opposition of the fieldsincreases in the same both actions neutralize each other and'at the sametime the coils and fields oppose each other. Since each half cycle ispassed by its corresponding unit -and the units are in parallel in theline 18 and 19, the two waves a, b will ap ear as a pulsating directcurrenton the ine.

The reciprocal property of the apparatus of Fig. 1 will now beexplained.

Let direct current from any source feed the units A and B by means oflines 18 and 19. Lines 18 and 19 may be brought directly into connectionor shorted and the switch 42 opened and switch 43' closed, whereupon thebattery or other direct current source 44 could be used as the source ofsup 1y, it having been possible to charge this attery, if a storagebattery, during the operations outlined above in'detail. Also let the.rotating elements of the whole system including the motor 35, be rotatedby some outside means and at such speed that selfinduction comes intoplay in the coils by the rapid change of magnetic flux caused by the1changing resultant field strengths of said 001 s. I Starting thedescription of operation of the apparatus all set as in the positionshown in Fig. 1,. the direct current divides equally between the twounits, A, B. Both coils rotate in a clockwise direction, for example. Itmay be of advantage in starting the a pparatus to have the machinerotating at the right speed before switching on the direct current thenboth units would be in some phase of their inductive and non-inductiveconditions. At A the resultant in a half revolution tends to decrease,at B at the same time it tends to increase. A decrease of lines aids thecurrent flowing, while an increase opposes the current. At A thedecreasing of lines caused by a coming together of the'coils into adifiierential combination by the rotation, increases the flow of currentthus tending to stop the fall of lines of the resultant, while at B therising of the/lines by opening of the coils into a non-difi'erentialcombination by the rotation, causes a counter electromotive force toappear and thus a reverse current which prevents the rise of lines ofthe resultant.

Stated in another way, at A as the lines of force of the resultant fallthe current rises causing a holding of. the lines because more currentflows, these two actions aiding actions and reactions the coils Ieach'other till zero rate of change of. fli1x= and maximum flow ofcurrent. imultaneously with these actions and reactionsthecoilslgradually turn into complete non-1nductive positions, allconditions thus allowing a free path through the coils.

At B. the rising lines of force of the resultant decrease the currentflowing and the decreasing of the current holds down the tions andreactions aiding each other till zero rate of chan e of flux and minimumflow of current' imultaneously with these gradually are turning into theinductive position,,all of which actions-thus choking out the current.Therefore the current from the source of supply is forced out andprevented from flowing thrpugh B, but, can flow through A. The positionsofthe rotating coils of both units have been reversed in this halfrevolution just completed, with all the current s'u ply going through A.

ow the units are ready regularly to shift the whole direct currentsupply from one unit to the other. In the next half revolun e, when thecoils are again parallel difi'erential; and no current can flow back.-

tion the lines of the resultant at begin gradually to rise and reach amaximum of and inductive. The'sa e half revolution causes the resultantlines of force at B'to fall gradually from a maximum to zero rate ofchange, when the coils are again parallel and non-inductive.

At A the action is to oppose the current fiowin while atlB thecurrentflow is aided. There ore the current leaves A and flows int'o'B till thewhole direct current supply is' now fiowing through B. This revolutiondirections, J 30 current remains in an-unvarying state of. current lines12 and 13 can also therefore caused the direct current to be a maximumfirst in A and then in B causing one cycle of alternating currenttonappean in the winding 10 which of course is now a secondary. If thiswinding 10 as a secondary is open or has resistance,the direct currentflow in the units will be regulated in a manner such as in anyalternating current transformer, by the reaction of the winding 14 (nowa primary) on itself. Each succeeding revolution causes the-directcurrent to rise to a maximum and .fall to zero again in one-unit, whileat the same time the direct currentfalls to zero and rises again toamaximum in the other, thus theunits alternate the flow of directcurrent. So each halfof the winding 14 has a current in onehalf fallingwhile the otherhalf has a rising current and vice versa, and flowing inopposite .there being thus consequent polarities and a falling north andrising" south or vice versa acting on the winding 14. The directcurrentfiflows out of one-unit in the same proportion that it flows intothe other. The result is that the'line direct c ntinuityfi Only enoughcurreiit flows in the unit that is made, for. the instant, inductiveorinactive to overcome the resistance ofits windings in which its actionis then like an alternating current transformer on no load. A weakresultant only then 00- For instance as the coils are shown in A isclosed while B is open. one due to the curs. the drawing, A has noresultant or a wea 10 lines of force of the resultant, these two acsmallcurrent flowin to overcome the resistto fall which aids the weak currentflowing,

this causes a little more resultant magnetism, which falling again byrotation reacts again keeping the resultant weak, but the currentincreases in strength till the resultant action and reaction becomeszero when the coils becomedifi'eren'tial and the. current a maximum. Atthe same time at B a weak resultant makes its appearance which causes anelectromotive force opposing that of the current flowing which reducesthe current and the resultant, but the rotation increases the resultantand so these actions and .reactions following each other till theresultant change and the current are zero and the coils noncoils willgovern this to some extent. The

tendency is toward a flat top wave with coils as shown, because thelonger the fields oppose each other, the longer the currentflows and theflatter would be thewave tops. In other words, at A with the coilsstationed as shown the resultant fall cannot take place at once becausethe resultant will tend to be crowded around in the direction ofrotation in the early part of the rotation; and at B no resultant canrise in the early part of the rotation because the two fields will stilli neutralize .each other almost completely When the alternating currentis started in the winding 19:, now, a primary, some of the current ofcourse is shunted through the motor 35 which causes it to take up theload and the outside power required to start the converter can bedispensed with, as it is then driven automatically.

Several such sets can be c eratedeach out of phase ,with the other so tat when all the secondaries are roperly connected to ether form of poyphase current is available.

anIyI 12o avin now shown how an alternatin g g alternated by the sameapparatus, it remains to be shown that'both operations can take placeatthe same time-1n the same appa-.

ratus. 9

Let line 18 and 19 be shorted and switch 42 op'ned and 43 closed,whichputs battery 44 in series with the rectifier. Alternating be con- I therevolving the alternating currentand waves are at a maxlmum;

pointed out previously that in the position of the coils shown in the;drawing, the unit A has just been closed to alternating current as wellas direct current while unit B has just been opened to both. Furthermorecoils are-in the osition when irect current Starting the explanation atunit B, the alternating current wave and direct current flow are at amaximum, as has/been said. Taking the alternating current wave first, asrotation continues, the wave drops in synchronism with the rotation,thus a resultant risesthattends to cause retardation of current flow andthecurrent falling tends to aid the current flow with the result thatthe current drops unretarded to zero in phase therefore with its own.electromotive force.

The coils turn from the difi'erential position at the same time. Theabove takes place in 90 of rotation. Going back to the start of this -90rotation and taking the direct current. 'The alternating currentresultant is keptat zero as above explained but since the direct currentis superposed on the alternating current it follows that thedirectcurrent resultant must tend;to appear and in doing so retards thecurrent flow and weak ens the resultant, but the resultant'increas'es.

on account of rotation which reacts on the current some more and sothese actions and reactions continue until there has been rotationthrough 90 and the direct current greatly reduced in strength.

At A in this same quarter turn the alternating current wave 1s absentbecause the coils are inductive, but the direct current begins to flowinto A as it flows out of B because the resultant fallin due to thecoils turning into the differentia relationship induces currents tendingto aid the current flow while the rising current tends to reduce it, thetwo neutralize each other keeping the resultant in the same weakstrength; and free passage is provided for the rising direct currentthrough A."

Going back to B and starting the second quarter turn the reversedalternating current wave risin cannot enter because Bis becomingnon-differential or inductive. The

direct current still continues to fall as in the first quarter and attheend of the second quarter has dropped to zero. At A-again in this secondquarter, the alternating current wave is rising in A because A isturning non-inductive or in other words, the actions.and reactionsneutralize each other and a free path is provided through A for thishalf cycle alternating current. The direct current continues to rise toa maximum in the second quarter at A as fast as it drops to zero in thesame quarter at B. In the same manner the direct current is shifted fromone unit to the other while the alternating current is barred from oneunit and then the other;-and the direct current and alternating currentwant to flow through the same units and in synchronism with each other;1with the result that they are superpose If several such pieces ofapparatus as Fig. 1 are used as rectifiers only and each rectifieroperates on an alternating current of different phase from the others,and these phases are regularly ordered, then when all rectifiers areconnected in series, a continuous direct current results. Thus a directcurrent flows through each rectifier while it is operating. Whether thedirect current comes from afbattery such as 44 or some other source orwhether it comes from several diiferent phasedrectifiers in series istherefore immaterial. What has just been ex lained with reference to thebattery 44 ho ds good when polyphase currents are used and the severalrectifiers are in series. The rectifi'ers themselves may be madepolyphase, when the same conditions are met and fulfilled. A three phaserectifier would require three units, each with its rotating. coil set atan angle of 120 and rangement.

- It now remains to explain Fig. 1 as a transformer by mutual induction,transforming from direct current to alternating current. Fig. 1 as sucha transformer is also reciprocal. It is best to explain Fig. 7 firstbecause the theory of the creation ,of a rotating magnet field is here"explained and this is the field required in the operation of Fig. l as amutual induction transformer. The positions of the coils of either unitthrough two revolutions are shown in Fig. 7 and whose actions areunderstood from the description in connection with Figs. 1, 4 and 6.. Ihave designated eight quarterly ositions of Fig. 7 by letters from s toa. direct current flows through the coils continuously for causing-thehomopolar rotating fields.

, At 8 the current in the two coils causes a resultant field northsouth.The first quarter turn of, the rotating coil brings it to position twith the resultant shifted in the direction of rotation one-eighth of arevolution; and being at a maximum strength. The second quarter turn ofthe coil is shown at u and the resultant shifted another onee'ighthturn. The third quarter turn shows the coils in the position at v wherethe re- I a sultant increases to a maximum from zero and dies down tozeroagain in one revolution. One revolutien therefore causes onecomplete cycle of alternating current iii a secdndary coil the rotatingfield acting as a primary. At t the resultantds a maximum; at '0 zero.This'wave is a true sine wave or nearly so; and is exa'ctly'like anymagnetic field that is gradually rising and falling; and thereis noreversing of polarity. \The north always travels upon the left and thesouth down on the right. The polarity may be reversed bychanging theconnections of the direct current supply but the polarity makesvlittledifferencem the operation. By feeding the coils with alternatingcurrentso that there is one revolution per half cycle of alternatingcurrent, than the polarity reverses with each revolution, which is arotirely disconnected from the remaining cirtating magnetic field andinduces in a secondary another alternating current. Turning backto Fig.1 and remembermg the explanation of Fig. 7 it will" be obvious how analternating current can beinduced in-the coils 45 by the rotation of themovable c'oils. Such coils 45 can also be used on Fig; 3. However, thetwo units should be encuits there shown, a direct current lead connectedwith terminal 26; terminal 20 and 23 are connected together; and theother direct current lead connected with The units are then in serieswith a direct current source. With 'the'polarities of the sets of coilsas shown in Fig. 1 then these counter electromotive forces. functionproperly.

hen one unit only is used," then in a half revolution the forces aid.the motor and oppose it the other half. Taking the coils in the positionas they are shown and rotating them clockwise'by the motor 35fed fromsome outside source, at A the resultant will 'fall; at B rise. Thereforethe alternate currents induced in the coils 45 at A and B" are exactlyin opposition as-to direction of flow,

. 'but they can be connected together so that they work together. To. dothis it is only necessaryto connect upper'terminal of coil 45 at A withupper terminal of coil 45 at B,

shown in Fig. 1

other set of units will have been an arc of 90. In'other words, thelatter i set are in advance of the former set'with regard to the fallofmagnetism,- hence the E. M. F.s induced "in the coils 45 'ofone set willbe behind those of the other set; b 90 in phase. Thesepolyphase M, F. 5cause polyphase currents to flow in the several coils 45, which currentsmay ployed s such, currents usually ate; Any numhe of such units as Fig.1 may be combined with the rotaryacoils of each set given a phasedisplacement from the others, then any number of phases can be drawnfrom the several coils 45. r

In the above cases where the coils are not Eaired as explained underFig. 7, power will e consumed unless they are so paired or provided withothermeans in some uses such as a flywheel for instance which flywheelmay be constituted by the rotating core and @011.-

my article on New commutator-less A. C. and D. Cfmachine page 1144 inthe Elec- In this connection I will call attention" to tm'calEmpem'mentr (now Science and Incaution) fonMarch, 1920, in which acomplete exposition of the above princi 1e and this and other a partusis given. Instead of using these cli rent they can be rectified by sucha rectifier as shown in Fig. .1. The direct current .01 any value willhave been converted to ano her direct current of any desired value by amethod as flexible and free of opening and closing contacts as anyalternating current transformer.

is, on noload then the cooperating coils as Let the secondary coils 45be open, that be em- 6 rrentsas alternating cur- '90 primary will chokeout the directcurrent in a manner similar to an alternating current'transformer on no load and will therefore be self-regulating justlike alternating current transformersI To explain" in a few words, takethe units A and B in ahalf revolution when connected in series for thepurpose of transforming by mutual induction, then B will cause aresultant to rise which induces a counter electromotive force tend: ingto choke out the current at A the current is aided by sultant, but sincethe units and the rising resultant. and decrease of oura falling rearein series rent at B are caused by the opening of the,

coils intothe inductive stage, of current at Acan not pass because B isbecoming ,inductive and any rise of current in the circuit is choked. Inthis case the rise and fall ofthe resultants must not be (on no load);no

any lncrease 115 simultaneous, the riseof one must occur first and thenthe fall of the other take place as explained in my copendingapplication Serial No. 354294. This is also one other reason ,why theunits 'must be paired. Therefore at B I own coils reduced to near zerobut also any other current is cause the entermg current tends toincrease the lines of forcealso the same as does the opening of thecoils and rising of resultant 130 prevented from entering benot only isthe current in its or non-differential, while the coils at D are,

at 60 and 61.

lines. Thus the two actions aid each other in choking out the primarydirect current only enough current flowing to overcome the resistance ofthe coils and to produce enough flux to overcome hysteresis. The nexthalf revolution reverses'the conditions of the units, but the actionsand reactions remain the same;- and soifor any number of units forpolyphase working. current is switched on while the units are inrotation, then no vcurrent can enter, on no load, because they are inseries and one or the other of the units is inductive. The variousdescriptions of Fi 1 given heretofore make clear how the c oking out ofthe primary is accomplished.

The motor 35 may receive current from the coils 45 after the apparatushas started.

Any frequency can be had by changin the speed, but the coils are woundbest or a certain frequency andthus speed. Increas-.

ing the speed above the frequency the coils are wound for, will increasethe impedance and therefore by varyin the speed we have a means forregulating tEe current flow with secondaries closed. The apparatus ofFigs. 1 and 3, whether actuated by self or mutual induction, can be usedwith dynamos and motors as a substitute for a commutator; and that as aunitary structure.

The rectifier shown at Figs. 3 and 5is also reciprocal. Here theprinciple is' the same as that disclosed in connection with Figs. 1 and4 but the method of operating is different for giving the cooperatingcoils their different properties. An understanding of Figs. 1 and 4 willtherefore make Figs. 3 and 5 readily comprehensible. An alternatingcurrent source feeds primary coils 57 of the transformer 58. Thesecondary 59 is split as in Fig. 1. The end terminals 60 and 61 lead totwo units 0 and ;D reepectively. Units 0 and D are similar. At J 62 isan iron core upon which are wound coils 63' and 64 in a differentialmanner. The lower terminals of both coils unite at 65 which in turnconnects with end terminal 60 of the secondary 59. The upper terminalsof coil 63 of both units unite at 66 and form'one terminal 67 of thedirect current line. The other direct current line 68 goes to thecentral point 69 of the split secondaryw 59.

The upper terminals of the coil 64 at both units make and break contactalternately through the vibrating lever 70 of a polarized relay 71.This-relay is in a shunt circuit of the secondar 59 and makes connectioncondenser 72 is in circuit with relay 71 to neutralize theself-induction of the relay windings. A connection 73 unites terminal 66and lever 70. The coil 64 at C being cut out, unit C is inductivenon-inductive or differential.-

As the. apparatus is set, current flowing Suppose t e in the secondary59 at this instant can pass through D but not C. The arrows show thepath of the current throu h D, which however, may, be in eitherirection. As the current a the secondar reverses or starts thegev'ersehalf cycle, t e relay throws the lever 70 in the opposite way whichopens the coil 64 at D and closes the same coil at C. The operation ofthe relay is the same as that of the well known polarized telephoneringer and therefore needs no spe cial comment. This reversed cyclethenfinds C open and D closed. Each succeeding cycle passes through thesame process and a unidirectional current appears on lines 67 and 68.The lever 70 operates in synchronism with the secondary. alternatingcurrent waves not makesimultaneously, o: if the relay does not respondat the start of current rise, there will be a break between thepulsations on the direct current line, that is, the beginning and end ofeach half cycle will be broken off or cut out.

Now to explain the above Fig. 3 in its reciprocal function, take theposition of the lever when .the relay is inert and in which the lever 70engages both of its contacts, apply a directcurrent at 67 and 68'and cutoifthe alternating current supply from primary 57. The direct currentflows equally well as far as induction is concerned through both units,therefore one-half of current from the direct current source appears ineach unit. Let the relay be operated from an outside source atpresent.Now let the lever 70 reverse and o env coil 64 at D and close the sameat C. he magnetism at D tries to rise but self-induction prevents it andthe direct current is choked out of D.

same time 64 at C makes, so that the greater current flow through C canat once find a path through parallel circuit now created at 0, otherwisethe direct current will be choked out of D and cannot flow at once 7 I kl L When the several relays 71 in several sets of apparatus such as Fig.3 make and break each out of phase with the other, theinpolyphasecurrents can be had from the several secondaries 57 when the latter areproperly "connected together.

Also several of these pieces of apparatus as rectifiers can be placed'inseries and each rectifier has the opening and closing-of its .contactsin a regular phased period one behind the other. The throw ofthe levercan be in phase in each unit with a alternating current of difierentphase, and when all are superposed unidirectionally there results acontinuous direct current .flow. Since a polyphasesystem produces adirect,current "and'the rectifier-s are in series, this isequivaaiaoepia friction, of course, for the present. This arrangement-ofcoils is very important and makes all the diflerence between success andfailure. The inert period in my system is known and recognized in theart as differentially wound and non-differentially wound. in the activeperiod, whereas the coils of the other systems in the inert period arewound in a way known and recognized in the art to produce consequentpolarities? while in the acti,ve period the 311's merely two separateelectromagnets' witii e di erential wound ever appears.

While I hve herein shown and particularly described equipment that maybe employed as embodiments .of apparatus of .my invention andr to'enableme to practice the coils no polarity whatsolent'to having a battery orother source of method thereof, I do not wish to be limited directcurrent in series with the equipment of ,Fig. 3 and thus 'the directcurrent is shifted "from one unit to the other-in synchronism with thewaves of the alternating current to be rectified.- As a reciprocal o arectifier and after starting, the reiay can be supplied with thealternating current closure,

transformed from the direct current and run automatically. No sparkingtakes place because thefLenz or induction law is reversed. To explain,when a contact is,opened there 'isno magnetism as it must first tend toappear; when the" contact is made the magnetism tends todisappear. WhenFig. 3 is used as a mutual induction transformer,

'the units are preferably connected in series as is the case in Fig.1.

It has been proposed, prior to this disto obtain the results aimed atherein, but in all these systems, the coilswhich aid and oppose eachother in alternate successive periods were 'not wound together or woundor placed over each other, hence more or less power must be consumed-indriving the rotary elements and when the elements should create a periodof absolute inertness, that is, be absolutely fi'ee from self-induction,they can not do so because of'the arrangement of the cooperating coils,whereby consequent poles are roduced instead of an to the precisedetails of circuit and arrangements of, equipment illustrated but havingunlike .poles adjacent each other. In

and desire to secure by Letters Patent the following ondary, two currentthrottling unlts, and,

a work circuit; said units provided with means for causing saidthrottling action and 4 1. An electromagnetic rectifier and curprovidingtwo paths of flow for said sup- .ply current, each of said unitsconsisting of a magnetic path and two coils, one of said coilsbeing-wound or placed over the other and both surrounding said magneticpath;

said throttling means of said units 0 eratl in synchronism with thewaves 0 current passing or tending to pas through them; said waves whenpassed appearing on said work circuit of a nature that of the supplycurrent.

opposite to 2. electromagnetic rectifier and current re'dressercomprising a source of supply current, a transformer, a plurality ofcurrent throttling units, and a work circuit; said 'units provided withmeans for causing said throttling action and'providing several paths offlow for saidsupply current; each of said units consistin of a magneticabsolute neutrality of polarity. In the coil path and two coils, one ofsaid coils being arrangement shown and described herein,

- the coils-are wound together. or wound or inductive and whennon-differential, they give the maximum inductive efiect of which a coilof their number of turns is capable of;

jthis is' so because in both cases both magnetic fields of bothcooperating coils are within the same space. This arrangement of coilsdescribed herein also reducesfthe power to drive them to acre,-disregarding means for causing saldthrotthng action and 130' wound orplacedv over the other and both surrounding said iron magnetic path;said throttling means of said units operating in .ply current, atransformer with a split secondary, two current throttling units and awork circuit; said units provided w-ith providin two aths of flowfor'said supply current; eac of said units consisting of a magnetic pathand two conductors one.

' through them; said waves when passed appearing on said work circuit ofa nature 0p posite' to that of the supply current.

4. An electromagnetic rectifier and cur-.

rent redresser comprising a source of supply current, a transformer, aplurality of current throttling units and a work circuit; said unitsprovided with means for causing said throttling action and provid- .ingseveral paths of flow for said supply current; each of saidunits'consisting of a magnetic path" and two conductors, one of saidconductors being wound or placed over the other and both surroundingsaid iron magnetic path; said throttling means of saidunits'o erating insynchronism with the waves 0 current passing ortending to pass throughthem; said waves when passed appearing on said work circuit of a nature5. An electromagnetlc rectifier and current redresser comprising asource of supplycurrent, two throttlin units and a work circuit; saidunits rovided with means for causing said throttllng action andprovidinga path of flow for said supply current; each of said units consisting ofa magnetic path and two grouped conductors and an individual one; one ofsaid grouped conductors being wound or placed over'the other and bothsurrounding said magnetic path; said individual conductor alsosurrounding said 'iron magnetic path; said throttling means of saidunits operating in synchromsm with the waves of current passlng ortending to pass through the individual conductor; said individualconductor constitutin the work pass appearing circuit; said waves whenon said work circuit terminals of'a nature opposite to that of thesupply current.

6. An electromagnetic rectifier and current redresser comprising asource'of su ply current, a pluralit of throttling umts and a workcircuit, sai units provided with mean for causing'said throttling actionand providing paths of flow for said supply current; each of said unitsconsistin of a magnetic path and two grouped con uctors and anindividual one; one of said grouped v conductors being wound or placedover the other and both surrounding said magnetic path; said individualconductor also surrounding said iron magnetic path; said throttlingmeans of said units operating in synchronism'with the waves of currentpassing or tending to pass throu h the individ ual conductor; saidindivi ual conductor constituting the work circuit; said waves whenpassed appearing on said work circuit terminals of a nature opposite tothat of the Suppl current.

11 an apparatus of the character described,jthe combination of two unitsin exact opposition of phase with each other, each unit consisting of aprimary composed of two superposed coils through which current isflowing and rotatable relative to one another, a magnetic circuit and asecondary coil surrounding said magnetic circuit, rotatable means forcausin successive, changes in the angular relations i between theprimary coils of each unit, w ereby a resultant magnetic flux is causedto rise and fall, said rise and fall of flux inducing alternatingelectromotive forces in said secondary coil.

, 8. In an apparatus of the character described, the combination of aprimary composed of two superposed coils through which current isflowing and rotatable re ative to one'another, a ma etic circuit and asecondary coil surrounding said magnetic circuit, rotatable means forcausin successive changes in the angular relationship between theprimary coi s, whereb a resultant magnetic flux is caused to rise andfall, said rise and fall of flux inducing alternating electromotiveforces in said secondary coil.

, In witness whereof I hereunto subscribe my4name this 20th day of MarchA. D., 191

RICHARD A. ENGLER.

